Air conditioning apparatus



Dec. 17, 1963 w. w. KENNEDY AIR CONDITIONING APPARATUS 3 Sheets-Sheet 1 Original Filed Oct. 13, 1961 INVENTOR.

WALTER \N. K ENNEDY ATT ORNEYS Dec. 17, 1963 W. W. KENNEDY AIR CONDITIONING APPARATUS Original Filed Oct. 13, 1961 3 Sheets-Sheet 2 INVENTOR. WALTER W. KENNEDY ATTORNEYS Dec. 17, 1963 W. W. KENNEDY AIR CONDITIONING APPARATUS Original Filed Oct. 13, 1961 3 Sheets-Sheet 3 United States Patent 3,1145% All CQNDHTIUNENG APPARATUS;

Walter W. Kennedy, Rockford, ill, assianor to Barber- (Iolnran Company, Rockford, TEL, a corporation of Illinois Continuation oi application Ser. No. 14$,il18, Oct. 13, 1961. This application Jan. 23, 1963, Ser. No. 254,546

2 Claims. (Cl. 236l3) This invention relates to apparatus for mixing primary or conditioned air and secondary or return air to provide a resultant mixture having a temperature such as to maintain a room to be conditioned at a desired temperature.

The invention is especially concerned with the conditioning of the air in a room having a false ceiling with a multiplicity of lighting fixtures mounted therein.

The primary object is to utilize the heat radiated from the lighting fixtures and accumulated adjacent the ceiling as a source for oontrollably tempering air supplied from a primary source at lower temperature before delivery thereof to a room to be cooled and maintained at an accurately regulated temperature.

The invention also resides in the simple and low cost construction of the duct work required to carry out the foregoing object.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in Which FIGURE 1 is a vertical cross-sectional View of the ceiling structure of a room equipped with an air conditioning system embodying the novel features of the pres ent invention.

FIG. 2 is a fragmentary perspective view of a portion of FIG. 1.

FIG. 3 is an enlarged longitudinal vertical section taken along the line 3-3 of FIG. 2.

FIG. 4 is an enlarged fragmentary view of a portion of FIG. 1 showing the dampers and the actuator therefor.

FIG. 5 is a fragmentary section taken along the line 5-5 of FIG. 4.

FIG. 6 is a fragmentary vertical sectional view similar to FIG. 3 and showing a modified construction.

FIG. 7 is a fragmentary perspective view of the modified construction.

In the drawings, the invention is shown incorporated in a system for maintaining the space lll below a false ceiling 11 of a room at a desired temperature by mixing in proper proportions cooled primary air supplied through an inlet duct 12 from a source 13 under pressure produced by a blower 14 with warm air drawn from the ceiling area of the room through inlet passages 15 and discharging the mixture into the room through openings 16 in one or more outlet fixtures l7. Herein, the openings l6 are at the ends of elongated passages 18 defined by a channel shaped casing 19 nested over a downwardly opening trofler 26 in which a plurality of fluorescent lamp bulbs 29* are disposed. The mixture of primary and secondary air is conveyed through a main duct 21 and delivered to the discharge outlets 17 through ducts 22 branching from a main duct which in modern buildings is usually disposed in a plenum space 23 between the ceiling 11 and a wall 24 spaced above the latter.

In the form shown, the return air inlets 15 to the plenum space are disposed along the side edges of lighting fixtures 25 similar in construction to the fixtures 1'7 and recessed into the false ceiling. In this instance, troflers 26 of the fixtures constitute the reflectors for lamp bulbs 27 and are set into the ceiling with the return air inlets 15 communicating directly with the plenum Patented Dec. 17 lQfiI-l space 23 above the ceiling. By the heat emitted from the lamps 26%, 27 and radiated from the room occupants, the area adjacent the ceiling 11 becomes warmed to a temperature substantially above that at the occupancy level. At the same time, the lamps heat the trotlers and, through the troiters, warm the air in the plenum space 23 by radiation and convection. This heated air is dissipated in the present instance by withdrawing air from the ceiling zone of the room and from the plenum in proper amounts and mixing the same with the cool primary air from the source 13 so as to temper the latter and deliver the mixture into the room at a temperature more nearly equal to that desired to be maintained at the occupancy zone.

Referring now to the form shown in FIGS. 1 to 4, aspiration of air from the plenum space 23 into the duct 21 is induced by a Venturi efiect produced by delivering air from the high pressure supply pipe 12. into a conduit 3% which is disposed within the duct 21 and terminates at a nozzle 31 having a substantially smaller cross-sectional area than the duct 21 and surrounded by a wall 32 near the upstream end of this duct. In this instance, the conduit and nozzle Ill are relatively flat and extend across substantially tlfi full width of the duct 21. A short distance beyond the nozzle and axially alined therewith is the throat or inlet 33 of a Venturi passage 34 whose walls diverge along the duct 21 to the full size of the latter. The throat is larger in area than the nozzle 31 so as to produce the desired Venturi effect and create a low pressure zone 35 enclosing the nozzle conduit and communicating with the plenum space 23 through a branch duct 36. Under the low pressure developed in the zone during the flow of high pressure air through the nozzle 31, air from the plenum chamber 23 is aspirated into and through the duct 36 and into the stream of high pressure air discharged from the nozzle 31.

The flow of conditioned air past the nozzle 31 and the flow of return air into the duct 2i are regulated and proportioned under the control of a thermostat 38 so as to maintain the mixture discharged into the room through the outlets 16 at a temperature which will compensate for the prevailing conditioning load and hold the occupancy zone of the room at the desired temperature. At the same time, the rates of the two flows are so correlated that the rate of delivery of the air mixture into the room is substantially constant for all of the different ratios of conditioned and aspirated air.

In the form shown in FIGS. 1 to 3, the amount of return air aspirated into the main supply duct 21 is determined by the position of a damper 40 disposed in the branch duct 36 and movable toward and away from the position shown in PEG. 3 to close and open the air passage. Trunnions 41 projecting from opposite ends of the damper are journaled in walls of the duct 36. The total amount of conditioned air delivered into the duct 21 may be varied by adjusting the position of a second damper 43 disposed in the main supply inlet 12 leading to the conduit 30.

At the same time, the amount of primary air flowing through the nozzle 31 and therefore the proportion of primary and return air delivered through the ceiling outlets 16 is determined by a damper 44 which in FIG. 2 is oifset from the nozzle conduit 30 and controls the area of an opening 45 for allowing primary air from. the inlet 12 to bypass the nozzle 31 and enter the throat passage 33 leading to supply duct 21. A trunnion at one end of this damper is journaled in a bracket 47 on the wall 32, a trunnion 46 at the other end being journaled in and projecting through a wall of the main duct 21.

The two dampers ill and 44 are coupled together for movement in unison but in opposite directions and at rates s) which are correlated with the velocity of the primary air flow and the relative sizes of the primary air passages 39, 45 and the return air passage 36, so as to maintain a constant volume of flow of the air mixture into the room. That is to say, closing of the damper to reduce the amount of primary air in the delivered mixture is accompanied by opening of the damper 4t; an amount such as to increase the How of return air just enough to compensate for the reduction in the rate of flow of the primary air. As a result, a change in the amount of aspirated air admitted to the duct 21 is balanced by an opposite change in the volume of primary air passed by the damper 44'. The total flow of air into the room is thus maintained at a substantially constant rate.

The dampers 4t) and 44 are actuated automatically by a conventional power operator 56 of the proportioning type having a reversely reciprocable output member 51 pivotally coupled by an adjustable joint 52 to the free end of a crank arm 53 which is fast on the outer end of the trunnion 46 of the damper 4 3. An arm 54 fast on this same trunnion is slotted at 55 and adjustably coupled by a joint 56 to a link 57 whose opposite end is similarly coupled adjustably by a joint 58 to the free end of an arm 62'} fast on the outer end of the outwardly projecting trunnion 41 of the damper 4-3. As shown in FIG. 5, the joints 56 and include a stud 59 shouldered at 61 and 61 and fastened to the slotted portion of the associated link by a nut 62. The rod 57 projects through a hole in the head of the stud and is clamped to the latter by a set screw 62?.

The arms 54 and on are clamped to the damper trunnions by screws 63 in positions such as to fully open the damper 44- and the primary air passage 45 when the damper 4t and the return air passage 36 are closed as shown in FIG. 2. Conversely, when the damper 4-5 is fully open as shown in FIG. 4, the damper 44 will close the primary air passage 45. A maximum amount of room air is then aspirated through the passage 36 and mixed with the jet of primary air then flowing only through the nozzle 31.

The damper operator 5t) and the thermostat 33 are of conventional constructions and operate with a proportioning action to change the positions of the dampers and produce a mixed air temperature which varies progressively within the narrow operating range of the thermostat. That is to say, a fall in the room temperature starts the operator 5% in a direction to increase the amount of room air aspirated into the mixture thus increasing the temperature of the latter until the dampers reach new positions corresponding to the room temperature at the thermostat. Conversely, a rise in the thermostat temperture initiates operation of the operator in the opposite direction and closing of the damper 4i and opening of the damper 44 to positions corresponding to such temperature rise.

Various types of operators and thermostats are available for proportioning the movements of the dampers with the changes in the room temperature as above described. For example, a suitable control of the electric type is the operator and thermostat manufactured by Barber-Colman Company and sold by the trade designations of MU 503-H and TSSlZl respectively.

With the dampers coupled together as above described, the lengths of the crank arms as and 6t and the length of the link 57 are adjusted to correlate the movements of the dampers with each other and the relative areas of the primary air passages 3h, 45 and the return air passage 36 so that a change in the amount of primary air delivered into the main duct will be balanced by an opposite change in the amount of return drawn into the duct. Thus, the opening and closing of the primary and return air passages to vary the mixture temperature as called for by the thermostat are achieved while at the same time maintaining the rate of delivery of the mixture into the room substantially constant at all times.

Instead of regulating the amount of primary air in the delivered mixture by varying the area of a by-passage around the nozzle 31 as above described, such regulation may be achieved by varying the fiow through the nozzle passage. Such a modification is shown in FIGS. 6 and '7 in which the primary air from the source 13 is delivered through a duct 64 which extends into the upstream end of the main duct 2-1 and terminates within the latter at a nozzle 65. The duct 6- extends across the full width of the main duct and the fiat top and bottom walls thereof cooperate with the opposed walls of the main duct to form passages 66 which are controlled by dampers 67 and open into the plenum space 23 at the upstream end of the duct.

As before, the nozzle cooperates with the surrounding walls of the main duct 21 to form a Venturi which operates during the discharge of a jet of primary air from tne nozzle to create sub-atmospheric pressures in the passages 66 and induce the aspiration of air through these passages. The amount of primary air flowing from the nozzle is controlled in this instance by a damper 68 of rectangular shape fulcrumed at 69 at the top wall of the duct 6 and swingable toward and way from an inclined seat 76 which defines the nozzle opening.

One end trunnion 71 of the damper pivot 69 projects outwardly through the adjacent wall of the duct 21 and is clamped by an arm 72 whose free end is coupled by an adjustable joint 73 of the character above described to one end of a link 74 of adjustable length, the other end of the link joined at 75 to the free end of a crank arm 76 fast on an outwardly projecting trunnion 77 of one of the dampers 67. Through a parallel motion linkage including cranks '73, 79 and a connecting link 39, the crank 76 is coupled to the projecting trunnion 81 of the other damper 67. A crank 82 fast on this trunnion is pivotally joined at 83 to one end of the actuator rod 51 of a reversible power operator 5%} or" the character above described.

It will be apparent that with the system above described heat accumulated near the ceiling of the room and radiated from the lamp bulbs is utilized as the sole source for controllabiy tempering the cool primary air delivered into the room to maintain the desired temperature thereof. The necessity of providing auxiliary heaters for the primary air or other more costly and completed arrangement is eliminated. Such use of the heretofore unused source of tempering heat is made possible by utilizing air returned from the room into the plenum space as the medium for receiving and transferring such heat into the primary air stream. Such transfer is accomplished simply by the short branch ducts 36 opening directly into the plenum space and communicating with the main duct 12. In this way, tie plenum space always available in modern buildings is utilized without added cost to provide all of the return air flow passages.

This application is a continuation of my pending application Ser. No. 145,018, filed October 13, 1961, now abandoned.

I claim as my invention:

1. In an air conditioning system, the combination of, a room within a building having a top wall and a false ceiling spaced therebelow and cooperating therewith to define a plenum space above the room, a plurality of eiectric lighting fixtures laterally spaced apart across said ceiling and havin troiiers set into the ceiling and said plenum space and secured to the ceiling, said trotfers having lamp bulbs therein lighting said room and heating said troifers so as to heat the air in said plenum space and adjacent said ceiling, an inlet passage through said ceiling establishing communication between the upper part of said room adjacent said ceiling and said plenum space for the upward flow of air from the room into such space, an outlet passage extending downwardly through said ceiling for the discharge of conditioned air into said room, a main duct disposed in said plenum space and having a branch opening into said plenum space, a branch duct disposed within and extending through the plenum space and establishing communication between said outlet passage and said main duct at a point downstream from said branch, means for supplying primary air under pressure to the inlet of said main duct, means within said main duct activated by the fiow of said primary air therethrough to induce the aspiration of heated air out of said plenum space and into said main duct through said branch and thereby induce the upward fiow of air from the room through said inlet passage and into said plenum space, a damper selectively adjustable to control the rate of aspiration of heated air out of said space through said branch, at second damper selectively adjustable to control the rate of flow of primary air into said main duet, a reversible power actuator having a driven member movable back and forth, a thermostat responsive to temperature changes in said room and controlling said actuator to dispose said member at all times in a position corresponding to the prevailing value of such temperature, and means coupling said member and the respective primary and aspirated air control dampers for movement of the latter in unison but in opposite directions whereby to change the flow of said primary air and reversely change the flow of aspirated air by corresponding amounts and thereby maintain a constant volume of the mixed air flowing into said room while utilizing the heat from said lamp bulbs to temper the air delivered into said room.

2. The combination defined in claim 1 in which one of said trofiers forms a Wall of said inlet pas-sage whereby the air flowing into said plenum space passes closely adjacent said one trofier and is heated thereby.

References ited in the file of this patent UNITED STATES PATENTS 2,440,052 Lingen et a l Apr. 20, 1948 2,737,875 Kurth et al Mar. 13, 1956 2,985,090 Quin May 23, 1961 

1. IN AN AIR CONDITIONING SYSTEM, THE COMBINATION OF, A ROOM WITHIN A BUILDING HAVING A TOP WALL AND A FALSE CEILING SPACED THEREBELOW AND COOPERATING THEREWITH TO DEFINE A PLENUM SPACE ABOVE THE ROOM, A PLURALITY OF ELECTRIC LIGHTING FIXTURES LATERALLY SPACED APART ACROSS SAID CEILING AND HAVING TROFFERS SET INTO THE CEILING AND SAID PLENUM SPACE AND SECURED TO THE CEILING, SAID TROFFERS HAVING LAMP BULBS THEREIN LIGHTING SAID ROOM AND HEATING SAID TROFFERS SO AS TO HEAT THE AIR IN SAID PLENUM SPACE AND ADJACENT SAID CEILING, AN INLET PASSAGE THROUGH SAID CEILING ESTABLISHING COMMUNICATION BETWEEN THE UPPER PART OF SAID ROOM ADJACENT SAID CEILING AND SAID PLENUM SPACE FOR THE UPWARD FLOW OF AIR FROM THE ROOM INTO SUCH SPACE, AN OUTLET PASSAGE EXTENDING DOWNWARDLY THROUGH SAID CEILING FOR THE DISCHARGE OF CONDITIONED AIR INTO SAID ROOM, A MAIN DUCT DISPOSED IN SAID PLENUM SPACE AND HAVING A BRANCH OPENING INTO SAID PLENUM SPACE, A BRANCH DUCT DISPOSED WITHIN AND EXTENDING THROUGH THE PLENUM SPACE AND ESTABLISHING COMMUNICATION BETWEEN SAID OUTLET PASSAGE AND SAID MAIN DUCT AT A POINT DOWNSTREAM FROM SAID BRANCH, MEANS FOR SUPPLYING PRIMARY AIR UNDER PRESSURE TO THE INLET OF SAID MAIN DUCT, MEANS WITHIN SAID MAIN DUCT ACTIVATED BY THE FLOW OF SAID PRIMARY AIR THERETHROUGH TO INDUCE THE ASPIRATION OF HEATED AIR OUT OF SAID PLENUM SPACE AND INTO SAID MAIN DUCT THROUGH SAID BRANCH AND THEREBY INDUCE THE UPWARD FLOW OF AIR FROM THE ROOM THROUGH SAID INLET PASSAGE AND INTO SAID PLENUM SPACE, A DAMPER SELECTIVELY ADJUSTABLE TO CONTROL THE RATE OF ASPIRATION OF HEATED AIR OUT OF SAID SPACE THROUGH SAID BRANCH, A SECOND DAMPER SELECTIVELY ADJUSTABLE TO CONTROL THE RATE OF FLOW OF PRIMARY AIR INTO SAID MAIN DUCT, A REVERSIBLE POWER ACTUATOR HAVING A DRIVEN MEMBER MOVABLE BACK AND FORTH, A THERMOSTAT RESPONSIVE TO TEMPERATURE CHANGES IN SAID ROOM AND CONTROLLING SAID ACTUATOR TO DISPOSE SAID MEMBER AT ALL TIMES IN A POSITION CORRESPONDING TO THE PREVAILING VALUE OF SUCH TEMPERATURE, AND MEANS COUPLING SAID MEMBER AND THE RESPECTIVE PRIMARY AND ASPIRATED AIR CONTROL DAMPERS FOR MOVEMENT OF THE LATTER IN UNISON BUT IN OPPOSITE DIRECTIONS WHEREBY TO CHANGE THE FLOW OF SAID PRIMARY AIR AND REVERSELY CHANGE THE FLOW OF ASPIRATED AIR BY CORRESPONDING AMOUNTS AND THEREBY MAINTAIN A CONSTANT VOLUME OF THE MIXED AIR FLOWING INTO SAID ROOM WHILE UTILIZING THE HEAT FROM SAID LAMP BULBS TO TEMPER THE AIR DELIVERED INTO SAID ROOM. 